Car-mounted disc player

ABSTRACT

A car-mounted disc player with an elastically supported drive unit including a turntable and a pickup; a clamper-supporting member rotatably supporting a clamper; a clamp mechanism for activating the clamper-supporting member to move toward or away from the drive unit so as to clamp or unclamp a disc between the turntable and the clamper; a lock mechanism for bringing the drive unit in a locked state or an unlocked state with respect to the chassis; and a change-over mechanism for activating the clamp and lock mechanisms. During change-over operations of the change-over mechanism for activating the clamp and lock mechanisms, the change-over mechanism can be halted at a half-locked position where the drive unit is brought in the locked state while the disc is kept in a clamped state by the turntable and the clamper.

BACKGROUND

1. Field of the Invention

The present invention relates to disc players for writing information ina disc such as a compact disc (CD) or a digital versatile disc (DVD)and/or for reading information written therein. In particular, thepreferred embodiments of the present invention relate to a car-mounteddisc player with a drive unit that is elastically supported on a chassisthrough an elastic member interposed therebetween. Further, thepreferred embodiments of the present invention relate to the use ofanti-vibration measures for switching the drive unit between a lockedstate and an unlocked state with respect to the chassis.

2. Description of the Related Art

A car-mounted disc player for use with a disc such as a CD or a DVD maybe susceptible to problems caused by external vibrations. For example, adisc player may contain a drive unit having an optical pickup, aturntable and so forth mounted that is fixedly supported on a chassis.In this instance, if an external vibration is exerted directly on theoptical pickup and the disc during play (during writing or readinginformation), the problem of sound skipping or the like may result. Inorder to prevent such a problem, a car-mounted disc player is usuallydesigned such that the drive unit is elastically supported on thechassis through the use of elastic members such as dampers so as toprevent an external vibration or shock from being exerted directly onthe drive unit and the disc during play. More particularly, thecar-mounted disc player of this type is equipped with a lock mechanismwhich switches the drive unit between a locked state and an unlock statewith respect to the chassis. In this regard, during play for writing orreading information in a state in which the optical pickup is set so asto face the disc placed on the rotating turntable, the lock mechanismholds the drive unit in the unlocked state of being elasticallysupported on the chassis, and during disc-transfer for inserting orejecting the disc, the lock mechanism holds the drive unit in the lockedstate with respect to the chassis by constraining the drive unit. Withthis arrangement, anti-vibration measures such as dampers prevent aproblem of sound skipping and the like even when an external vibrationor shock is exerted during play. Further, by defining the positionalrelationship between the locked drive unit and a disc slot formed on thefront surface of the chassis, an operation of inserting or ejecting thedisc can be performed without any problems.

This car-mounted disc player has a structure in which a pair of slidersmoving back and forth driven by a motor are disposed at both sides ofthe chassis and the lock mechanism and a clamp mechanism for bringing adamper in or out of contact with the disc are activated in accordancewith an advance or retreat position of the two sliders. These twosliders move in synchronization with each other by means of a linkmechanism or the like. In a standby state in which the disc is notloaded, the damper is held at an upper position where the damper isbrought out of contact with the turntable and the drive unit is broughtin the locked state. Also, when the disc is transferred to a playingposition of the disc player, the damper moves down so as to press thedisc on the turntable and the drive unit is brought into the unlockedstate from the locked state.

The car-mounted disc player of this type may be used as a car-mountednavigation apparatus in addition to as an apparatus for playing back amusic disc or the like, and the disc player is sometimes shipped in apackage set together with a disc (CD-ROM, DVD, or the like) having mapinformation written therein. In this case, although there are providedtwo systems for shipping the disc player; the one in an ejected state inwhich the disc is ejected from the disc player during transport and theother in a chucked state in which the disc is loaded in the disc layerduring transport, the other system is usually employed in order toreduce the volume of the packed disc player. However, according to theforegoing related art, in the chucked state in which the disc placed atthe playing position is clamped by the damper and the turntable, sincethe drive unit is brought into the unlocked state from the locked stateand is elastically supported on the chassis, when a strong externalvibration or shock is exerted on the disc player during transport, thedisc hits against a stationary component such as the chassis and hencegets damaged.

Also, in the car-mounted disc player of this type, especially in thedisc player for a DVD, the tilt of a laser beam emitted from the opticalpickup must be adjusted at the final assembling stage of the disc playerwhile the disc is rotating. However, since the drive unit remains in theunlocked state while the disc is played, a adjustment of the tilt of theoptical pickup or the turntable is very difficult to the need to pressthe elastically supported drive unit by using, for example, an adjustingjig inserted in the chassis.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a car-mounted discplayer that prevents a disc from damage during transport even when thedisc player is transported with a disc loaded therein and also thatallows for less complicated adjusting a tilt of a pickup or a turntable.

A car-mounted disc player according to a preferred embodiment of thepresent invention includes a drive unit having at least a turntable anda pickup and elastically supported on a chassis having an elastic memberinterposed therebetween; a clamper-supporting member rotatablysupporting a clamper; a clamp mechanism for activating theclamper-supporting member to relatively move toward or away from thedrive unit so as to bring a disc in a clamped state or an unclampedstate between the turntable and the clamper; a lock mechanism forbringing the drive unit in a locked state or an unlocked state withrespect to the chassis; and a change-over mechanism for activating theclamp mechanism and the lock mechanism. During change-over operationsfor activating the clamp mechanism and the lock mechanism, thechange-over mechanism can be halted at a half-locked position where thedrive unit is brought in the locked state while the disc is beingclamped by the turntable and the clamper.

Since the change-over mechanism for activating the clamp mechanism andthe lock mechanism can be halted at the half-locked position where thedrive unit is brought in the locked state while the disc is beingclamped by the turntable and the clamper, even when the car-mounted discplayer is shipped in a state of having the disc loaded therein, the discis prevented from damage during transport. Further, because the driveunit can be locked at the half-locked position while the disc isrotating, the adjustment of the tilt (skew) of the pickup or theturntable may be done without an additional jig for locking the driveunit.

In the disc player having the above-described structure, although thechange-over mechanism suffices as long as it can activate the clampmechanism and the lock mechanism to perform the respective change-overoperations between clamping and unclamping the disc and between lockingand unlocking the drive unit, it is preferable that the change-overmechanism have at least one slide member disposed on the chassis, andthe clamp mechanism and the lock mechanism operate in accordance with aback-and-forth movement of the slide member. In this case, the slidemember halting at the half locked position may be temporally fixed tothe chassis by a connecting member such as an adhesive tape, atemporally fixing pin, or a screw, since the slide member can bereliably prevented from displacement during transport or during a skewadjusting work.

Also, it is preferable that the disc player having the above-describedstructure include position-detecting means for detecting the fact thatthe slide member reaches to the half-locked position, since the slidemember can be easily halted at the half-locked position. Suchposition-detecting means can be formed by, for example, a detectingswitch disposed on the chassis side and a drive portion disposed on theslide member side. In this case, when the drive portion is arranged soas to activate the detecting switch at the half-locked position, theslide member can be easily halted in accordance with an operating signaloutput from the detecting switch. Alternatively, the position-detectingmeans can be formed by first and second marks disposed on or in theslide member and the chassis, respectively. In this case, when the firstand second marks are arranged so as to mate with each other at thehalf-locked position, the half-locked position is visually detected withease so that the slide member is reliably halted at this position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a car-mounted disc player according to anembodiment of the present invention;

FIG. 2 is a perspective view of the disc player from which a top chassisis removed;

FIG. 3 is a perspective view of the disc player from which the topchassis and a guide member are removed;

FIG. 4 is an exploded perspective view of a drive unit, the guidemember, first and second slide members, and so forth provided in thedisc player;

FIG. 5 is a perspective view of a link mechanism, the slide members, andso forth provided in the disc player;

FIG. 6 is a plan view of the link mechanism in an ejected state;

FIG. 7 is a plan view of the link mechanism during play;

FIGS. 8A and 8B respectively illustrate the first and second slidemembers provided in the disc player, both lying at an ejected position;

FIGS. 9A and 9B respectively illustrate the first and second slidemembers lying at a half-locked position;

FIGS. 10A and 10B respectively illustrate the first and second slidemembers lying at a playing position;

FIG. 11 is a perspective view of the first slide member in an ejectedstate;

FIG. 12 is a perspective view of the first slide member lying at thehalf-locked position;

FIG. 13 is a perspective view of the first slide member during play;

FIG. 14 is a plan view of a disc-positioning mechanism provided in thedisc player;

FIG. 15 is a front view of the disc-positioning mechanism;

FIG. 16 is a right side view of the disc-positioning mechanism;

FIG. 17 is a plan view of the disc-positioning mechanism illustrating astate in which a small disc is loaded;

FIG. 18 is a front view of the disc-positioning mechanism illustrating astate in which the small disc is loaded;

FIG. 19 is a plan view of the disc-positioning mechanism illustrating astate in which a large disc is loaded;

FIG. 20 is a front view of the disc-positioning mechanism illustrating astate in which the large disc is loaded;

FIGS. 21A to 21D are plan views of the disc-positioning mechanismillustrating an operation of positioning the large disc;

FIG. 22 is a sectional view of the guide member provided in the discplayer; and

FIG. 23 is a perspective view of a major part of a modification ofposition-detecting means for detecting a half-locked position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A car-mounted disc player according to the present embodiment can dealwith two types of discs D having diameters of 8 cm and 12 cm.Hereinafter, the small and large discs having diameters of 8 cm and 12cm are respectively denoted by SD and LD, if necessary.

As shown in FIGS. 1 to 3, the car-mounted disc player has a chassis 1and a top chassis 2 that form an external skeleton thereof and which aremade by bending a metal plate. The chassis 1 has a front plate 1 c atthe front thereof and a slit-like slot 1 d formed by cutting the upperportion of the front plate 1 c, through which a disc D (small disc SD orlarge disc LD) is inserted into or ejected from the disc player. Thecentral portion of the top chassis 2 is cut out on a large scale so thatthe top chassis forms a frame-like shape. Also, the top chassis 2 isfixed to the upper surface of the chassis 1 with screws and has a guidemember 3 and a roller 4 disposed thereunder, forming a disc-transfermechanism.

As shown in FIG. 4, the guide member 3 has a flat plate 3 a and a pairof side plates 3 b formed by bending the right and left sides of theflat plate 3 a. Each of the side plates 3 b has two drive pins implantedtherein. The flat plate 3 a has an under surface, each of right and lefthalves thereof having a gradually tapered shape, slating downward fromthe central portion thereof toward the right and left side plates 3 b.Also, the flat plate 3 a has a pair of long narrow shaped recesses 3 dat the right and left portions thereof, formed so as to protrude fromthe lower surface to the upper surface thereof, and has a pair of bends3 e at the front and rear edges thereof protruding upward. Since thedrive pins 3 c are engaged with corresponding cam grooves formed in apair of slide members, which will be described later, when the two slidemembers move in a back-and-forth direction in synchronization with eachother, the guide member 3 moves up and down while keeping a state ofbeing parallel to the chassis 1.

As shown in FIG. 22, the guide member 3 is made by pressing a compositeof a metal plate 3A and a resin layer 3B previously coated on thesurface of the metal plate 3A. In this press working, the foregoing sideplates 3 b, recesses 3 d, and bends 3 e are formed. The metal plate 3Asuffices as long as it has such a stiffness that its mechanical strengthis sufficient for the guide member 3, and the resin layer 3B suffices aslong as it has such a slippery property that the surface of the disc Dis prevented from damage when the disc D is transported while beingclamped by the guide member 3 and the roller 4. In a preferredembodiment, the metal plate 3A is made from a steel plate havingsubjected to a chromate treatment with a trivalent chrome and having athickness of 1 mm, and the resin layer 3B is made from a fluorocarbonresin (ethylene-tetrafluoroethylene (ETFE) copolymer) film and having athickness of 20 μm. Thus, the composite is obtained by previouslybonding the fluorocarbon resin film to the steel plate. Since the ETFEcopolymer film is in general unlikely bonded to another member, onesurface of the ETFE copolymer film is subjected to a primer treatment; aprimer and the film are chemically bonded by heat; and the primer andthe steel are thermally deposited to each other so that the fluorocarbonresin film serving as the resin layer 3B is bonded to the steel plateserving as the metal plate 3A.

Each of right and left halves of the roller 4 has a trapezoidal coneshape gradually becoming larger in diameter from the central portiontoward the end thereof, and the roller 4 is driven to rotate in either anormal direction or a reverse direction by a power from a motor (notshown). The roller 4 is rotatably supported at the rear portion of aroller bracket 5. The front portion of the roller bracket 5 is turnablysupported by right and left latching plates 1 b (see FIG. 3) formed bybending portions of the bottom surface of the chassis 1. Since both endsof the roller 4 are also engaged with corresponding cam grooves of thetwo slide members, which will be described later, when the two slidemembers move in the back-and-forth direction in synchronization witheach other, the roller bracket 5 turns about its engaging portion withthe latching plates 1 b so as to activate the roller 4 to move up anddown. With this structure, the disc D inserted through the slot 1 d canbe clamped by the lower surface of the guide member 3 and the roller 4.In this occasion, when the roller 4 is arranged such that thelarge-diameter portions thereof face the two recesses 3 d of the guidemember 3, the central portion of the disc D is reliably clamped by theguide member 3 and the roller 4.

As shown in FIGS. 2 and 3, the chassis 1 has a pair of detecting levers6 turnably supported on the bottom surface thereof and also has acircuit board 7 (see FIGS. 11 to 13) fixed thereto and under thedetecting levers 6. Each of the detecting levers 6 has a detecting pin 6a formed in a standing manner at the front thereof, and the upper end ofthe detecting pin 6 a is inserted in an arch-shaped guide hole 2 aperforated in the top chassis 2 (see FIG. 1). The detecting levers 6 areurged by a spring (not shown) in a direction in which the two detectingpins 6 a come close to each other, and the detecting lever 6 lying atthe left side in the drawing has a drive portion 6 b disposed at therear thereof. The circuit board 7 has a switch (not shown) mountedthereon. When the outer periphery of the disc D inserted through theslot 1 d abuts against at least one of the detecting pins 6 a and thecorresponding detecting lever 6 accordingly turns outward by apredetermined angle, the foregoing switch is activated so as to start adrive motor for the foregoing roller 4 in accordance with the turning ofthis detecting lever 6.

The car-mounted disc display has a drive unit 8 disposed in the mainbody thereof, and the drive unit 8 has a drive chassis 9 formed bybending a metal plate. The drive chassis 9 is elastically supported onthe bottom surface of the chassis 1 by elastic members such as aplurality of dampers 10 (see FIGS. 6 and 7) or coil springs (not shown).The drive chassis 9 has lock pins 9 a and 9 b disposed in a protrudingmanner at the left and right sides thereof, respectively, and also has alock pin 9 c and a lock pin (not shown) disposed in a protruding manneron the right side surface and the lower surface thereof, respectively.In addition, the drive chassis 9 has an optical pickup 11, a spindlemotor 12, and so forth mounted thereon. The spindle motor 12 has aturntable 13 fixed to the rotating axis thereof (see FIG. 15).Furthermore, the drive chassis 9 has an arm clamp (clamper-supportingmember) 14 disposed thereon. The arm clamp 14 is supported so as to bevertically translated since a pair of guide grooves 14 a formed on theright and left side surfaces thereof are respectively engaged with thelock pins 9 a and 9 c of the drive chassis 9. The arm clamp 14 has aprojecting piece (not shown) integrally formed by bending a portion ofthe left side surface thereof and also has a pair of front and reardrive pins 14 b disposed on the right side thereof in a protrudingmanner. In addition, the arm clamp 14 has a damper 15 rotatablysupported thereon, and the pair of drive pins 14 b of the arm clamp 14are inserted in a pair of corresponding cam holes 16 b of a drive arm 16(see FIG. 16). The drive arm 16 is supported at the right end of thedrive chassis 9 so as to be slidable in the back-and-forth direction andis elastically urged by a spring 17 toward the slot 1 d. Also, the drivearm 16 has an engaging projection 16 a which engageably faces aprojection of the right slide member, which will be described later.

As shown in FIGS. 14 to 16, the drive chassis 9 has a pair ofpositioning members 18 and 19 turnably supported thereon. Thepositioning members 18 and 19 respectively position the center holes ofthe discs SD and LD, having different diameters from each other, withrespect to the turntable 13. The left positioning member 18 is formed byan arm lever (an abutment) 18 b, made from a synthetic resin and havinga toothed portion 18 a at the rear thereof, and by a regulating arm (aregulatory portion) 18 c made from a leaf spring. The regulating arm 18c is cantilevered such that its base portion is fixed to the front ofthe arm lever 18 b and its free end elastically abuts against the lowersurface of the arm clamp 14. The right positioning member 19 is formedby an arm lever (an abutment) 19 b, made from a metal plate and having atoothed portion 19 a at the rear thereof, and by a regulating arm (aregulatory portion) 19 c made from a leaf spring. The regulating arm 19c is cantilevered such that its base portion is fixed to the front ofthe arm lever 19 b and its free end also elastically abuts against thelower surface of the arm clamp 14. The two positioning members 18 and 19turn in synchronization with each other by arranging the correspondingtoothed portions 18 a and 19 a to engage with each other and are urgedby a spring (not shown) in a direction in which the fronts thereof comecloser to each other.

Also, the drive chassis 9 has a first-end detecting lever 36 turnablysupported thereon and a lock lever 20 supported thereon so as to behorizontally movable. The first-end detecting lever 36 has a detectingportion 36 a contactable with the outer periphery of the disc SD havinga diameter of 8 cm. The detecting portion 36 a lies at the centerbetween the two arm levers 18 b and 19 b. The arm lever 18 b of thepositioning member 18 and the first-end detecting lever 36 are connectedto each other via a pin and a long hole (both not shown) such that thefirst-end detecting lever 36 turns toward the remotest side of the drivechassis 9 in conjunction with the outward turning of the leftpositioning member 18. In addition, the first-end detecting lever 36 hasa relay member (not shown) connected to the end thereof lying on theother side of the detecting portion 36 a so that the turning of thefirst-end detecting lever 36 is selectively transmitted to a second-enddetecting lever, which will be described later, via the relay member.The lock lever 20 has a lock portion 20 a formed at the rear thereof,which is engageable with the arm lever 18 b of the left positioningmember 18, and is urged by a spring (not shown) to the left of the drivechassis 9. The lock lever 20 has a pressing portion 20 b disposed at thefront thereof so as to face the drive portion 6 b of the foregoing leftdetecting lever 6. When the disc LD having a diameter of 12 cm isinserted into the disc player, the drive portion 6 b presses thepressing portion 20 b so that the lock lever 20 is moved rightward inorder to remove the restriction of the positioning member 18 caused bythe foregoing lock portion 20 a.

The foregoing two slide members are disposed on the inner surfaces ofright and left side surfaces 1 a of the chassis 1. Hereinafter, the leftand right slide members are respectively referred to as a first slidemember 21 and a second slide member 22. The two slide members 21 and 22are composed of a synthetic resin and are supported on the chassis 1 soas to be movable in the back-and-forth direction.

As shown in FIGS. 6 and 7, the chassis 1 has a second-end detectinglever 37 and a motor 23 serving as a drive source for the first slidemember 21 turnably supported and disposed, respectively, at the leftremote end of the bottom surface thereof. The second-end detecting lever37 has a detecting portion 37 a contactable to the outer periphery ofthe disc LD having a diameter of 12 cm and is urged clockwise by aspring (not shown). The power of the motor 23 is transmitted to a gear38 lying at the final stage of a gear train via the gear train. The leftfirst slide member 21 has a rack 24 facing the gear 38 and supported onthe bottom plate thereof so as to be movable in the back-and-forthdirection by a predetermined distance. Although the rack 24 is urgedbackward by a spring (not shown) so as to move away from the gear 38,when the second-end detecting lever 37 turns counterclockwise and ispressed forward by the end of the second-end detecting lever 37 on theother side of the detecting portion 37 a, the rack 38 engages with thegear 38. Thus, when the rack 24 is moved forward by a predetermineddistance by the power of the motor 23, the moving force of the rack 24is transmitted to the first slide member 21, and thus a rack portion 21h formed on the bottom plate of the first slide member 21 engages withthe gear 38. With this structure, the power of the motor 23 istransmitted to the left first slide member 21 via the gear 38, and themovement of the first slide member 21 is transmitted to the right secondslide member 22 via a link mechanism 25.

As shown in FIG. 5, the link mechanism 25 is formed by first and secondlink levers 26 and 27, which are turnably supported on the bottomsurface of the chassis 1. The left end of the first link lever 26 isturnably connected to the rear end of the first slide member 21; theright end of the second link lever 27 is turnably connected to the rearend of the second slide member 22; and a pin 26 a implanted in the rightend of the first link lever 26 is inserted in a cam hole 27 a perforatedin the left end of the second link lever 27. Accordingly, when the firstlink lever 26 turns in accordance with the back and forth movement ofthe first slide member 21, the pin 26 a moves within the cam hole 27 aso as to cause the second link lever 27 to turn, thereby allowing thesecond slide member 22 to move back and forth in the same direction asthe first slide member 21. That is, the first slide member 21 is adriver powered by the motor 23, and the second slide member 22 is anidler movable in synchronization with the first slide member 21.

The chassis 1 has a lock lever 28 turnably supported on the innersurface of the left side plate 1 a. Since the lock lever 28 turns as thefirst slide member 21 moves back and forth, in accordance with thismovement, the lock pin 9 a disposed at the left of the drive chassis 9is engaged or disengaged. Meanwhile, the chassis 1 has a lock slidemember 29 and a link arm 30 supported on the inner surface of the rightside plate 1 a thereof so as to be movable in the back-and-forthdirection and to be turnable, respectively. Since the link arm 30 turnsas the second slide member 22 moves back and forth, in accordance withthis movement, the lock slide member 29 moves back and forth in theopposite direction to the second slide member 22. The lock slide member29 has a lock hole 29 a perforated therein, which engages with ordisengaged from the lock pin 9b disposed at the right of the drivechassis 9. Also, the chassis 1 has a center lock lever 31 having a lockarm 31 a turnably supported on the bottom surface thereof. Since thecenter lock lever 31 turns in conjunction with the first link lever 26,a lock pin (not shown) disposed at the central portion of the lowersurface of the drive chassis 9 is engaged or disengaged in accordancewith this movement.

As shown in FIGS. 8 to 13, the left first slide member 21 has aplurality of cam grooves 21 a to 21 e formed on the inner surfacethereof and also has first and second drive portions 21 f and 21 gintegrally formed on the inner bottom thereof. The first slide member 21has a cam-shaped pressing piece 21 j formed on the inner surfacethereof. Since the pressing piece 21 j lies at a position in which itcan get under the foregoing projecting piece integrally formed with thearm clamp 14, when the pressing piece 21 j gets under the projectionpiece, the arm clamp 14 is moved up. Meanwhile, the foregoing circuitboard 7 has first and second detecting switches 32 and 33 mountedthereon. The first detecting switch 32 has an actuator portion 32 aprotruding out from the left side surface of the circuit board 7 and thesecond detecting switch 33 has an actuator portion 33 a protrudingupward from the circuit board 7. The first detecting switch 32 isactivated when the first drive portion 21 f presses the actuator portion32 a during the forward movement of the first slide member 21. Thus, thefirst drive portion 21 f and the first detecting switch 32 serve asposition-detecting means which can detect a half-locked position, whichwill be described later. The second detecting switch 33 is activatedwhen the second drive portion 21 g presses the actuator portion 32 aduring the forward movement of the first slide member 21, and thus thesecond drive portion 21 g and the second detecting switch 33 serve as aroad-end detecting means. The right second slide member 22 also has aplurality of cam grooves 22 a to 22 c formed on the inner surfacethereof and has a protrusion 22 d formed on the upper surface thereof.FIGS. 8A to 10A illustrate the first slide member 21 and FIGS. 8B to 10Billustrate the second slide member 22, both viewed from the inside ofthe main body of the disc player.

Both ends of the roller 4 engage with the cam grooves 21 a and 22 a ofthe two slide members 21 and 22, and left two and right two of the fourdrive pins 3 c of the guide member 3 engage with the cam grooves 21 band 21 c of the slide member 21 and the cam grooves 22 b and 22 c of theslide member 22, respectively. The left lock pin 9 a of the drivechassis 9 engages with the cam groove 21 d of the first slide member 21,and a pin 28 a implanted in the lock lever 28 engages with the camgroove 21 e of the first slide member 21. In addition, the engagingprojection 16 a of the drive arm 16 engageably faces the protrusion 22 dof the second slide member 22, and the pair of drive pins 14 b of thearm clamp 14 are inserted in the pair of cam holes 16 b. Also, the rightlock pin 9 b of the drive chassis 9 engages with the lock hole 29 a ofthe lock slide member 29 which moves in the opposite direction to thesecond slide member 22 via the link arm 30. With this structure, whenthe first and second slide members 21 and 22 move back and forth in thesame direction, in accordance with this movement, the roller 4 and theguide member 3 move up and down; the drive chassis 9 is locked andunlocked; and the arm clamp 14 moves up and down.

As described above, in the present embodiment, the pair of drive pins 14b and the projecting piece of the arm clamp 14, the pressing piece 21 jof the first slide member 21, and the drive arm 16 form a clampmechanism for clamping and unclamping the disc D between the damper 15and the turntable 13 by activating the arm clamp 14 to move in anup-and-down direction along which the arm clamp 14 moves toward and awayfrom the drive chassis 9. Also, the lock pins 9 a and 9 b of the chassis9 and the lock pin on the lower surface of the same, the cam groove 21 dof the first slide member 21, the lock lever 28, the lock slide member29, the link arm 30, and the center lock lever 31 form a lock mechanismwhich locks or unlocks the drive unit 8 to or from the chassis 1. Inaddition, the first and second slide members 21 and 22 and the linkmechanism 25 form a change-over mechanism for activating the foregoingclamp mechanism and lock mechanism to perform the respective change-overoperations.

As shown in FIG. 3, the chassis 1 has a positioning hole 34 perforatedin the left side plate 1 a thereof, and the first slide member 21 has apositioning hole or depression (not shown) formed therein which issimilar to the positioning hole 34. By inserting a temporal fixing pin35 in and latching it with the positioning hole 34 or the positioningdepression from the outside of the left side plate 1 a of the chassis 1,the first slide member 21 is prevented from moving at a half-lockedposition, which will be described later, with respect to the chassis 1.Alternatively, when the positioning depression of the first slide member21 and the temporal fixing pin 35 are formed as a screw hole and a malescrew, respectively, the first slide member 21 may be firmly fixed byscrewing the temporary pin into the positioning depression.

During ejection (in a standby state) where the disc player has no disc D(small disc SD or large LD) inserted in the main body thereof, the firstand second slide members 21 and 22 remain at a retreat position on theremotest side of the chassis 1. As shown in FIGS. 8A and 8B, during theabove-mentioned ejection, both ends of the roller 4 lie at correspondingupper positions and on the near side of the cam grooves 21 a and 22 a,and the drive pins 3 c of the guide member 3 lie at corresponding middlepositions and on the near side of the cam grooves 21 b, 22 b, 21 c, and22 c. With this arrangement, the guide member 3 is held at a descentposition corresponding to the slot 1 d, and the roller 4 is held at anascent position in which the roller 4 is pressed against the lowersurface of the guide member 3. The left lock pin 9 a of the drivechassis 9 is restrained by the cam groove 21 d of the first slide member21 and the lock lever 28 from the rear and front directions; the rightlock pin 9 b of the same is latched with the inner periphery of the lockhole 29 a of the lock slide member 29; and also, the lock pin (notshown) on the lower surface of the drive chassis 9 is latched with thelock arm 31 a of the center lock lever 31. As a result, the drive unit 8remains in a locked state of being fixedly supported on the chassis 1 inthe back-and-forth direction as well as in the horizontal and verticaldirections. In addition, since the engaging projection 16 a of the drivearm 16 is pressed against the protrusion 22 d of the second slide member22 and thus the drive arm 16 also remains at its retreat position, asshown in FIG. 16, the two drive pins 14 b of the arm clamp 14 move upalong the corresponding two cam holes 16 b of the drive arm 16. Also,since the pressing piece 21 j of the first slide member 21 gets underthe projecting piece of the arm clamp 14 and lifts this projecting pieceupwards, the arm clamp 14 is held in an ascend position in which itdetaches from the drive chassis 9. With this arrangement, as shown inFIG. 15, the damper 15 lies right above the turntable 13 so as toprovide a space in which the disc D is inserted. In this stage, theregulating arms 18 c and 19 c of the two positioning members 18 and 19respectively extend from the arm levers 18 b and 19 b toward the damper15 and elastically abut against the lower surface of the arm clamp 14,and the lock portion 20 a of the lock lever 20 is latched with the armlever 18 b so as to restrain the turning of the positioning member 18.

In such a standby state, when the disc D (small disc SD or large discLD) starts to be inserted into the main body of the disc player from theapproximate center of the slot 1 d, the outer periphery of the frontside of the disc D in the inserting direction thereof comes into contactwith the detecting pins 6 a of the two detecting levers 6, and theinsertion force of the disc D causes the two detecting levers 6 to turnoutward. When a switch (not shown) detects the fact that at least one ofthe detecting levers 6 turns by a predetermined angle, a motor (notshown) starts to rotate the roller 4. When the disc D is furtherinserted, the front portion of the disc D in the insertion direction isclamped by the lower surface of the guide member 3 and the roller 4, andthe rotation force of the roller 4 causes the disc D to be transferredin the main body of the disc player. Because the drive chassis 9 ismaintained in a locked state and the arm clamp 14 is held at a standbyposition above the drive chassis 9, the drive chassis 9 and the armclamp 14 (i.e., the turntable 13 and the damper 15) have a transferroute for the disc D inserted therebetween. When the disc D is detectedby the above-mentioned switch detects the fact that the disc D isinserted, the motor 23 disposed at the left remote end on the chassis 1starts to rotate.

When the inserted disc D is a small disc SD having a diameter of 8 cm,since the outward turning of the two detecting levers 6 forms a smallangle, the pressing portion 20 b of the lock lever 20 does not come intocontact with the drive portion 6 b of the left detecting lever 6 duringthe transfer of the disc SD, and the two positioning members 18 and 19remain in a lock state of being restrained at a predetermined open angle(at a first position). When the disc SD is inserted from the left sideof the slot 1 d, although the drive portion 6 b of the left detectinglever 6 causes the lock lever 20 to slide rightward once, since thedetecting levers 6 return to their original states while the disc SD ismoving toward the remote side, upon transfer of the disc SD to aposition in which the center hole of the disc SD lies right above theturntable 13, the two positioning members 18 and 19 return to the lockstate. With this arrangement, when the disc SD passes through the spacebetween the drive chassis 9 and the arm clamp 14 and is transferred tothe remote side of the chassis 1, as shown in FIGS. 17 and 18, twopoints of the outer periphery of the front side of the disc SD in thetransfer direction come into contact with the fronts of the two armlevers 18 b and 19 b, and thus the center hole of the disc SD isproperly positioned with respect to the turntable 13. In this case,since the regulating arms 18 c and 19 c of the two positioning members18 and 19 respectively extend from the fronts of the arm levers 18 b and19 b and elastically abut against the lower surface of the arm clamp 14,even when an external vibration or shock is exerted on the disc player,the disc SD during transfer does not pass over above the two arm levers18 b and 19 b and is accordingly reliably positioned by the twopositioning members 18 and 19 while being guided by the regulating arms18 c and 19 c.

When the disc SD is positioned with respect to the turntable 13 asmentioned above, since the front of the disc SD comes into contact withthe detecting portion 36 a and the first-end detecting lever 36 turnscounterclockwise, the second-end detecting lever 37 also turnscounterclockwise via the relay member (not shown) so as to engage therack 24 with the gear 38. Subsequently, when the rack 24 moves on thebottom plate of the first slide member 21 up to a position where therack 24 is limited to move, the rack 24 and the first slide member 21are actually integrated, whereby the first slide member 21 starts tomove forward and the rack portion 21 h engages with the gear 38. As aresult, the rotating power of the motor 23 is transmitted to the leftfirst slide member 21 via the gear 38; the movement of the first slidemember 21 is transmitted to the right second slide member 22 via thelink mechanism 25; and the first and second slide members 21 and 22start to move from the retreat position on the remotest side of thechassis 1 to an advance position thereof. In addition, upon the disc SDbeing positioned with respect to the turntable 13, because the twodetecting levers 6 detach from the disc SD and return to their originalpositions, the foregoing switch detects this movement and stops theroller 4 to rotate. Alternatively, the rotation of the roller 4 may bestopped by detecting the turning of the second-end detecting lever 37with a switch (not shown).

Meanwhile, when the inserted disc D is a large disc LD having a diameterof 12 cm, since the outward turning of the two detecting levers 6 formsa wider angle than in the case of the disc SD, during the transfer ofthe disc LD, the pressing portion 20 b of the lock lever 20 is pressedby the drive portion 6 b of the left detecting lever 6 and thus the locklever 20 moves rightward. As a result, the two positioning members 18and 19 are released from the restriction of the lock portion 20 b of thelock lever 20. With this arrangement, when the disc LD passes throughthe space between the drive chassis 9 and the arm clamp 14 and istransferred to the remote side of the chassis 1, as shown in FIGS. 21Aand 21D, two points of the outer periphery of the front side of the discLD in the transfer direction come into contact with the fronts of thetwo arm levers 18 b and 19 b, and then the transfer force of the disc LScauses the two positioning members 18 and 19 to turn outwards so as towiden an angle formed between these members. In accordance with thismovement, the two regulating arms 18 c and 19 c slide on the lowersurface of the arm clamp 14. When the two positioning members 18 and 19is stopped at a predetermined open angle (at a second position) by astopper (not shown), as shown in FIGS. 19, 20, and 21D, the outerperiphery of the disc LD abuts against the inner circumferential surfaceof the two arm levers 18 b and 19 b.As a result, the center hole of thedisc LD is properly positioned with respect to the turntable 13. Also,in this case, since the regulating arms 18 c and 19 c of the twopositioning members 18 and 19 respectively extend from the fronts of thearm levers 18 b and 19 b and elastically abut against the lower surfaceof the arm clamp 14, even when an external vibration or shock is exertedon the disc player, the front side of the disc LD in the transferdirection is guided by the regulating arms 18 c and 19 c, whereby thedisc LD during transfer does not pass over above the two arm levers 18 band 19 b and is accordingly reliably positioned by the two positioningmembers 18 and 19.

As stated previously, since the first-end detecting lever 36 and the armlever 18 b of the positioning member 18 are connected to each other viathe pin and the long hole (both not shown), although the first-enddetecting lever 36 turns such that the detecting portion 36 a thereofdetaches from the disc LD in conjunction with the positioning member 18,the rotation force of the first-end detecting lever 36 is cut off by therelay member so as not to be transmitted to the second-end detectinglever 37. When the disc LD is positioned with respect to the turntable13, the outer periphery of the disc LD during transfer comes intocontact with the detecting portion 37 a so as to turn the second-enddetecting lever 37, whereby the rack 24 is pressed by the second-enddetecting lever 37 and thus engages with the gear 38. Then, in thesimilar fashion to the foregoing small disc SD, the rotating power ofthe motor 23 is transmitted to the left first slide member 21 via thegear 38, and the first and second slide members 21 and 22 start to movefrom the retreat position on the remotest side of the chassis 1 to theadvance position. When the disc LD is positioned with respect to theturntable 13, the rotation of the roller 4 is stopped.

When the disc D (small disc SD or large LD) is positioned with respectto the turntable 13 as described above and the rotating power of themotor 23 is transmitted to the left first slide member 21, the movementof the first slide member 21 is transmitted to the second slide member22 via the link mechanism 25 formed by the first link lever 26 and thesecond link lever 27. This results in the movement of the left and rightslide members 21 and 22 from the retreat position to the advanceposition in the direction indicated by the arrow E in FIG. 6 insynchronization with each other without generating a substantial phaselag.

While the first and second slide members 21 and 22 are moving from theretreat position shown in FIGS. 8A and 8B to a position shown in FIGS.9A and 9B, both ends of the roller 4 move from the corresponding upperpositions to lower positions of the cam grooves 21 a and 22 a, and thedrive pins 3 c of the guide member 3 move from the corresponding middlepositions to lower positions of the cam grooves 21 b, 22 b, 21 c, and 22c and then to corresponding middle positions of sloped portions of thesame. As a result, the guide member 3 moves down from the foregoingdescent position to its lowest position and then moves up so as toreturn to the lower position, and the roller 4 moves to its descentposition and thus detaches from the lower surface of the disc D.Although the lock pin 9 a moves within the cam groove 21 d, since thepin 28 a of the lock lever 28 moves in a horizontal portion of the camgroove 21 e, the lock pin 9 a remains in being latched with the locklever 28. Likewise, since the second slide member 22 moves in a range soas not to affect the attitude of the link arm 30, the lock slide member29 remains at rest; accordingly, the lock pin 9 b is also latched withthe lock hole 29 a of the lock slide member 29, and the lock pin (notshown) on the lower surface of the drive chassis 9 remains in beinglatched with the lock arm 31 a of the center lock lever 31, whereby thedrive unit 8 remains in a locked state of being fixedly supported on thechassis 1. Meantime, when the protrusion 22 d of the second slide member22 moves forward, the drive arm 16 moves forward by a predetermineddistance urged by the spring 17, while the engaging projection 16 a ofthe drive arm 16 remains in contact with the protrusion 22 d. Thus, thepair of drive pins 14 b of the arm clamp 14 moves down along thecorresponding cam holes 16 b of the drive arm 16. At the same time, whenthe first slide member 21 moves forward, the pressing piece 21 jdetaches from the projecting piece of the arm clamp 14, thereby causingthe arm clamp 14 to move down so as to come closer to the drive chassis9. As a result, the damper 15 supported by the arm clamp 14 comes closeto the turntable 13, and the periphery of the center hole of the disc Dis chucked between the turntable 13 and the damper 15. While the disc Dis being placed on the turntable 13 from its transfer height, the guidemember 3 also moves down together with the damper 15 due to the camshapes of the cam grooves 21 b and 21 c and the cam grooves 22 b and 22c of the slide members 21 and 22, respectively, while the guide member 3remains in contact with the upper surface of the disc D, whereby thedisc D positioned by the two positioning members 18 and 19 is reliablychucked between the turntable 13 and the damper 15. Also, since theregulating arms 18 c and 19 c of the corresponding positioning members18 and 19 are deformed due to their own elasticity while elasticallyabutting against the lower surface of the descending arm clamp 14, thearm clamp 14 is not prevented by the regulating arms 18 c and 19 c frommoving up and down.

When the first and second slide members 21 and 22 move to the positionshown in FIGS. 9A and 9B, the drive unit 8 remains in the locked stateof being fixedly locked to the chassis 1 while the disc D is beingchucked (clamped) between the turntable 13 and the damper 15. In thefollowing description, this position will be referred to as ahalf-locked position.

While the first and second slide members 21 and 22 are moving from thehalf-locked position shown in FIGS. 9A and 9B to the advance position onthe nearest side of the chassis 1 shown in FIGS. 10A and 10B, the twoends of the roller 4 moves to the lower positions on the remote sides ofthe cam grooves 21 a and 22 a, and the drive pins 3 c of the guidemember 3 move from the corresponding middle positions of the slopedportions of the cam grooves 21 b, 22 b, 21 c, and 22 c to thecorresponding upper positions of the same. As a result, the guide member3 moves from the descent position to the ascend position and detachesfurther from the upper surface of the disc D, and also the roller 4 isheld at the descend position away from the lower surface of the disc D,thereby providing a large space, in which the disc D is not preventedfrom rotation, between the guide member 3 and the roller 4. Also, thelock pin 9 a moves to a position at which it disengages from the camgroove 21 d, and the pin 28 a moves from the horizontal portion of thecam groove 21 e to a sloped portion of the same so as to turn the locklever 28, whereby the latching of the lock pin 9 a with the lock lever28 is released. In addition, since the link arm 30 turns such that asthe second slide member 22 moves from the position shown in FIG. 9B tothe position shown in FIG. 10B, the lock slide member 29 moves to theremote side of the chassis 1, the latching of the lock pin 9 b with thelock slide member 29 is released, and since the center lock lever 31turns to a large extent in conjunction with the first link lever 26 (seeFIG. 7), the latching of the lock pin on the lower surface of thechassis 9 with the center lock lever 31 is also released at the sametime. As a result, the drive chassis 9 is elastically supported on thechassis 1 by the dampers 10 or the like and the drive unit 8 is changedover from the locked state to the unlock state.

The disc player is brought into a playing state as described above. Inthis playing state, when the spindle motor 12 is driven to rotate, theturntable 13, the disc D, and the damper 15 rotate integrally so thatinformation is written in and/or read from the disc D by the opticalpickup 11. During ejection where the slide members 21 and 22 remain atthe retreat position on the remotest side of the chassis 1, as shown inFIG. 11, the second drive portion 21 g of the first slide member 21 liesaway from the actuator portion 33 a of the second detecting switch 33.Meanwhile, when the slide members 21 and 22 move to the advance positionon the nearest side of the chassis 1 so as to bring the disc player intothe playing state, as shown in FIG. 13, the second drive portion 21 gcomes into contact with the actuator portion 33 a so as to turn on thesecond detecting switch 33. Accordingly, when the rotation of the motor23 is stopped by using an output signal from the second detecting switch33 as a road end signal, the slide members 21 and 22 move to the advanceposition on the nearest side of the chassis 1 and halt at a playingposition. Instead of stopping the rotation of the roller 4 uponcompletion of the above-mentioned transfer of the disc D, the rotationof the roller 4 may be stopped when the second detecting switch 33 turnson. In order to eject the disc D, from which reading information hasbeen completed, to the outside of the main body of the disc player, whenan ejection button (not shown) is operated, the motor 23 starts torotate in the opposite direction so as to perform an operation in asequence opposite to the above-mentioned operation, so that the firstand second slide members 21 and 22 move backward from the advanceposition and return to the retreat position shown in FIGS. 8A and 8B.

The car-mounted disc player according to a preferred embodiment isarranged such that the slide members 21 and 22 can be brought to a haltat the half-locked position during their assembly or between their finalinspection and shipment. More particularly, when the slide members 21and 22 move from the retreat position shown in FIGS. 8A and 8B to thehalf-locked position shown in FIGS. 9A and 9B, as shown in FIG. 12, thefirst drive portion 21 f of the first slide member 21 abuts against theactuator portion 32 a so as to activate the first detecting switch 32 toturn on; thus, by stopping the motor 23 in accordance with an operatingsignal of the first detecting switch 32, the slide members 21 and 22 canbe reliably brought into a halt at the half-locked position. Then, asshown in FIG. 3, by inserting the temporal fixing pin 35 into thepositioning hole 34 from the outside of the chassis 1 at the half-lockedposition, and then by latching the front of the temporal fixing pin 35with the positioning hole or positioning depression (not shown) formedin the first slide member 21, the chassis 1 and the first slide member21 can be connected to each other so as not to move mutually at thehalf-locked position as long as the temporal fixing pin 35 is not pulledout.

Accordingly, when the completely assembled car-mounted disc player isshipped and transported from its factory in a state of being loaded witha disc D such as a CD-ROM or DVD, for example, used for navigation, thedrive unit 8 is maintained in the locked state while the disc D is beingchucked at the half-locked position; therefore, even when a strongexternal vibration or shock is exerted on the disc player duringtransport, the loaded disc D is reliably prevented from hitting againstthe chassis 1 or members and the like fixed to the chassis 1, and thusprevented from damage. Also, when a tilt of a laser beam emitted fromthe optical pickup 11 is adjusted at the final assembling stage of thedisc player while the disc D is being driven to rotate, since the driveunit 8 is maintained in the locked state while the disc D is beingchucked at the half-locked position, the disc D can be driven to rotatewhile the drive chassis 9 having the optical pickup 11 mounted thereonis kept in the locked state, whereby such an adjusting work can beeasily done. When the temporal fixing pin 35 is pulled out by apurchaser of the disc player, the chassis 1 and the first slide member21 are disconnected from each other. Thus, when the disc player isinstalled at a predetermined location in a car body for operation, theslide members 21 and 22 move back and forth without halting at thehalf-locked position, whereby the slide members 21 and 22 activate theclamp mechanism and the lock mechanism to perform the respectivechange-over operations. The disc player may have a CPU or the likehaving a program previously installed therein for moving the slidemembers 21 and 22 from the half-locked position to the playing positionshown in FIGS. 10A and 10B when the disc player is delivered and has aninitial electric power applied thereon. Although the temporal fixing pin35 serves as a connecting member for temporally fixing the chassis 1 andthe first slide member 21 (and the second slide member 22) at thehalf-locked position, in place of the temporal fixing pin 35, anadhesive tape, clips, or the like may be used, or a combination of themmay be used. Meanwhile, since the rack portion 21 h of the first slidemember 21 engages with the gear 38 at the half-locked position shown inFIG. 9A, the first slide member 21 is in connection with the motor 23.Accordingly, the temporal fixing pin 35 is not always necessary.However, when such a connecting member is disposed, the slide member 21is reliably maintained in the half-lock state even when a stronger shockis exerted on the disc player.

FIG. 23 is a perspective view of a main part of a modification of theposition-detecting means for detecting the half-locked position. Asshown in the figure, when a first mark such as a projection 39 is formedon the upper surface of the first slide member 21 integrally therewithand also a second mark such as a groove 40 is formed in the top chassis2 fixed on the upper portion of the chassis 1 so that the projection 39and the groove 40 mate with each other at the half-locked position, thehalf-locked position is visually detected with ease without the firstdetecting switch 32, whereby the first slide member 21 is reliablyhalted at this position. In this case, the motor 23 may be energized soas to move the first slide member 21 to the half-locked position;alternatively, the first and second slide members 21 and 22 can bemanually moved to the half-locked position. The marks of theposition-detecting means at the half-locked position are not limited tothe projection 39 and the groove 40; instead, they may be printed marks,engraved marks, or the like.

Although the disc D is clamped between the damper 15 and the turntable13 by moving down the damper 15 in the foregoing embodiment, on thecontrary, the turntable may be moved up relative to the damper so as toclamp the disc D therebetween. The lock mechanism and the change-overmechanism are not limited to those in the foregoing embodiment, and canbe modified as needed.

1. A car-mounted disc player comprising: a drive unit elasticallysupported on a chassis having an elastic member between the drive unitand the chassis, the drive unit including a turntable and a pickup; aclamper-supporting member rotatably supporting a clamper; a clampmechanism operable to activate the clamper-supporting member to bring adisc in a clamped state or an unclamped state between the turntable andthe clamper; a lock mechanism operable to place the drive unit in alocked state or an unlocked state with respect to the chassis; and achange-over mechanism operable to activate the clamp mechanism and thelock mechanism, wherein the change-over mechanism may be halted at ahalf-locked position where the drive unit is brought in the locked statewhile the disc is kept in a clamped state by the turntable and theclamper.
 2. The car-mounted disc player of claim 1, wherein thechange-over mechanism comprises at least one slide member movablysupported on the chassis.
 3. The car-mounted disc player of claim 2,further comprising a connecting member for temporally fixing the slidemember to the chassis at the half-locked position.
 4. The car-mounteddisc player of claim 2, further comprising a position-detecting meansfor detecting when the slide member reaches the half-locked position. 5.The car-mounted disc player according to claim 4, wherein said at leastone slide member comprises first and second slide members disposed onboth sides of the chassis, wherein said first and second slide membersare connected by a link mechanism.
 6. The car-mounted disc playeraccording to claim 5, wherein the position-detecting means detects whenone of said first and second slide members reaches the half-lockedposition.
 7. The car-mounted disc player according to claim 4, whereinthe position-detecting means detects when said at least one slide memberreaches the half-locked position.
 8. The car-mounted disc player ofclaim 2, further comprising a detecting switch disposed on the chassisside and a drive portion disposed on the slide member side.
 9. Thecar-mounted disc player of claim 8, wherein the drive portion activatesthe detecting switch when the slide member reaches to the half-lockedposition.
 10. The car-mounted disc player of claim 8, further comprisinga motor operable to drive the slide member to move back and forth. 11.The car-mounted disc player of claim 10, wherein the motor stops whenthe detecting switch is activated by the drive portion.
 12. Thecar-mounted disc player of claim 2, further comprising a first markdisposed on the slide member side and a second mark disposed on thechassis side, wherein the first and second marks mate when the slidemember reaches to the half-locked position.
 13. A car-mounted discplayer comprising: a drive unit elastically supported on a chassishaving an elastic member between the drive unit and the chassis, thedrive unit including a turntable and a pickup; a clamper-supportingmember rotatably supporting a clamper; a clamp mechanism operable toactivate the clamper-supporting member to bring a disc in a clampedstate or an unclamped state between the turntable and the clamper; alock mechanism operable to place the drive unit in a locked state or anunlocked state with respect to the chassis; and at least one slidemember movably supported on the chassis and operable to activate theclamp mechanism and the lock mechanism, wherein during a movement of theslide member for activating the clamp mechanism and the lock mechanism,the slide member may stop at a half-locked position.
 14. The car-mounteddisc player of claim 13, further comprising a connecting member operableto fix the slide member to the chassis at the half-locked position. 15.The car-mounted disc player of claim 13, further comprisingposition-detecting means for detecting when the slide member reaches tothe half-locked position.
 16. The car-mounted disc player according toclaim 15, wherein said at least one slide member comprises first andsecond slide members disposed on both sides of the chassis, wherein thetwo slide members are connected by a link mechanism.
 17. The car-mounteddisc player according to claim 16 wherein the position-detecting meansdetects if one of the first and second slide members reaches to thehalf-locked position.
 18. The car-mounted disc player of claim 13,further comprising a detecting switch disposed on the chassis side and adrive portion disposed on the slide member side, wherein the driveportion activates the detecting switch when the slide member reaches thehalf-locked position.
 19. The car-mounted disc player of claim 18,further comprising a motor operable to driving the slide member moveback and forth.
 20. The car-mounted disc play of claim 19, wherein themotor stops when the detecting switch is activated by the drive portion.21. The car-mounted disc player according to claim 13, furthercomprising a first mark disposed on the slide member side and a secondmark disposed on the chassis side, wherein the first and second marksmate when the slide member reaches to the half-locked position.
 22. Acar-mounted disc player comprising: a drive unit elastically supportedon a chassis having an elastic member between the drive unit and thechassis, the drive unit including a turntable and a pickup; aclamper-supporting member rotatably supporting a clamper; a clampmechanism operable to activate the clamper-supporting member to place adisc in a clamped state or an unclamped state between the turntable andthe clamper; a lock mechanism operable to place the drive unit in alocked state or an unlocked state with respect to the chassis; at leastone slide member, movably supported on the chassis, operable to activatethe clamp mechanism and the lock mechanism in accordance with itsback-and-forth movement; and position-detecting means operable to detectwhen the slide member reaches to a half-locked position, wherein theposition detecting means may stop slide member at the half-lockedposition.
 23. The car-mounted disc player of claim 22, furthercomprising a connecting member operable to hold the slide member to thechassis at the half-locked position.
 24. The car-mounted disc player ofclaim 22, wherein the position-detecting means comprises a detectingswitch disposed on the chassis side and a drive portion disposed on theslide member side.
 25. The car-mounted disc play of claim 23, whereinthe drive portion activates the detecting switch the slide memberreaches the half-locked position.
 26. The car-mounted disc player ofclaim 24, further comprising a motor operable to drive the slide membermove back and forth, wherein the motor stops when the detecting switchis activated by the drive portion.
 27. The car-mounted disc player ofclaim 22, further comprising a first mark disposed on the slide memberside and a second mark disposed on the chassis side, wherein the firstand second marks mate when the slide member reaches the half-lockedposition.
 28. The car-mounted disc player of claim 22, wherein said atleast one slide member comprises first and second slide members disposedon both sides of the chassis, wherein said first and second slidemembers are connected by a link mechanism.